My experience
Beginning of Dec '13 I came over backwards on a short little nothing climb because of a woop and a void in the snow from a tree top. I ended up head down in my trench, my 2011 M8 rolled on top of me and with the bars upright the throttle stayed pinned for 5 seconds, long enough to destroy my brand new jacket, the side of my pack and dig 1/2" into my left arm. If it had kept spinning the track at 80mph it would have taken my left arm and I might have bled out, it took 5 hrs to get to the hospital. End of sledding that weekend, missed 3 days of work to monitor for compartment syndrome, missed the following weekend of sledding and had to get overgrowing tissue coming out of the wound burned off... WEAR A TETHER! The dumb part is I didn't start wearing one after my dad's riding buddy got tangled up in a tree with his yamaha and needed reconstructive surgery to repair his quad(the muscle, not a 4 wheeler).
Beginning of Dec '13 I came over backwards on a short little nothing climb because of a woop and a void in the snow from a tree top. I ended up head down in my trench, my 2011 M8 rolled on top of me and with the bars upright the throttle stayed pinned for 5 seconds, long enough to destroy my brand new jacket, the side of my pack and dig 1/2" into my left arm. If it had kept spinning the track at 80mph it would have taken my left arm and I might have bled out, it took 5 hrs to get to the hospital. End of sledding that weekend, missed 3 days of work to monitor for compartment syndrome, missed the following weekend of sledding and had to get overgrowing tissue coming out of the wound burned off... WEAR A TETHER! The dumb part is I didn't start wearing one after my dad's riding buddy got tangled up in a tree with his yamaha and needed reconstructive surgery to repair his quad(the muscle, not a 4 wheeler).